The present invention relates to a novel polynucleotide sequence which encodes a novel polypeptide belonging to the class of proteins known as G-protein coupled receptors (GPCRs). The present invention also relates, inter alia, to processes for producing the polypeptide and its uses.
Cells and tissues respond to a wide variety of extracellular signalling molecules through the interaction of these molecules with specific cell-surface receptors. One such class of receptors are known as G-protein coupled receptors (GPCRs) and these are characterised by containing a series of 7 hydrophobic transmembrane segments. Upon binding an extracellular ligand to its receptor, intracellular signals are initiated via interactions with heterotrimeric G proteins which, in turn, can lead to a number of different intracellular events depending upon which receptor has been activated. For example some GPCRs influence adenyl cyclase activity whereas others act via phospholipase C.
Members of the GPCR superfamily respond to a wide variety of ligands including small molecule amines (such as serotonin, dopamine, acetylcholine), lipid-derived mediators (such as LpA), amino acid derivatives (such as glutamate) and neurotransmitter peptides and hormones (such as neurokinin, galanin, glucagon, gastrin). Although GPCRs are activated by a broad range of ligands, it should be noted that individual GPCRs have a small and very specific repertoire of ligands. Based upon an analysis of the primary structure of a novel GPCR, it is now possible to classify them into specific sub-families, thereby narrowing the range of potential ligands.
In many cases, the endogenous ligands of GPCRs are relatively small, enabling them to be mimicked or blocked by synthetic analogues. For example drugs such as prazosin, doxazosin, cimetidine, ranitidine are all effective antagonists of their respective target GPCRs.
Thus, as the modulation of GPCRs can have therapeutic consequences, there is a continued need to provide new GPCRs and their associated agonists and antagonists.
In a broad aspect, the present invention relates to novel amino acid sequences. In this regard, a specific novel amino acid sequence has been isolated and it is to be understood that the invention covers that sequence as well as novel variants, fragments, derivatives and homologues thereof.
In another broad aspect, the present invention relates to novel nucleic acid sequences. In this regard, a specific novel nucleic acid sequence has been isolated and it is to be understood that the invention covers that sequence as well as novel variants, fragments, derivatives and homologues thereof.
Thus, in brief, some aspects of the present invention relate to:
1. Novel amino acids.
2. Novel nucleotide sequences.
3. Assays using said novel sequences.
4. Compounds/compositions identified by use of said assays.
5. Expression systems comprising or expressing said novel sequences.
6. Methods of treatment based on said novel sequences.
7. Pharmaceutical compositions based on said novel sequences.
Other aspects concerning the amino acid sequence of the present invention and/or the nucleotide sequence of the present invention include: a construct comprising or capable of expressing the sequences of the present invention; a vector comprising or capable of expressing the sequences of the present invention; a plasmid comprising or capable of expressing the sequences of the present invention; a cell transfected or virally-transduced with a construct/vector/plasmid comprising or capable of expressing the sequences of the present invention; a tissue comprising or capable of expressing the sequences of the present invention; an organ comprising or capable of expressing the sequences of the present invention; a transformed host comprising or capable of expressing the sequences of the present invention; and a transformed organism comprising or capable of expressing the sequences of the present invention. The present invention also encompasses methods of expressing the same, such as expression in a micro-organism; including methods for transferring the same.
For ease of reference, aspects of the present invention are now discussed under appropriate section headings. However, the teachings under each section are not necessarily limited to each particular section.
In the following commentary references to xe2x80x9cnucleotide sequence of the present inventionxe2x80x9d and xe2x80x9camino acid sequence of the present inventionxe2x80x9d refer respectively to any one or more of the nucleotide sequences presented or discussed herein and to any one or more of the amino acid sequences presented or discussed herein. Also, and as used herein, xe2x80x9camino acid sequencexe2x80x9d refers to peptide or protein sequences and may refer to portions thereof. In addition, the term xe2x80x9camino acid sequence of the present inventionxe2x80x9d is synonymous with the phrase xe2x80x9cpolypeptide sequence of the present inventionxe2x80x9d. Also, the term xe2x80x9cnucleotide sequence of the present inventionxe2x80x9d is synonymous with the phrase xe2x80x9cpolynucleotide sequence of the present inventionxe2x80x9d.